CN117713740A - Surface acoustic wave resonator, preparation method thereof and filter - Google Patents
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Abstract
The invention provides a surface acoustic wave resonator, a preparation method thereof and a filter, which relate to the technical field of semiconductor devices, and the invention is characterized in that at least one heat conducting layer is formed above an interdigital electrode, and is subjected to imaging treatment to remove part of the heat conducting layer, sound velocity is reduced in a removed area, so that a speed reduction is formed in a clearance area between specific interface positions (an electrode finger strip and a opposite bus bar or an area boundary with the largest sound velocity between the electrode finger strip and a false electrode finger strip) to obtain a larger sound velocity difference, so that a transverse mode is restrained by reflecting clutter, and the purpose of further reflecting the transverse mode in different directions is realized by optimizing the change of the width of the removed area in the propagation direction of a main acoustic mode, such as a weighted gradual change mode and the like, so that the condition of resonance formation of the heat conducting layer is destroyed, thereby restraining the clutter, avoiding energy dissipation and finally improving the performance of the surface acoustic wave resonator. The heat conduction layer can also enable heat generated by the surface acoustic wave resonator to be more easily emitted to a certain extent, so that the maximum power tolerance effect of the surface acoustic wave resonator can be improved.
Description
Technical Field
The invention relates to the technical field of semiconductor devices, in particular to a surface acoustic wave resonator, a preparation method thereof and a filter.
Background
A SAW (Surface Acoustic Wave ) resonator is a short term of a surface acoustic wave resonator, is a special filter device manufactured by utilizing the piezoelectric effect and the physical characteristics of surface acoustic wave propagation, and is widely used in various fields, such as a radio frequency field. Wherein a surface acoustic wave is an elastic wave in which energy is concentrated near a surface.
In the current surface acoustic wave product design, the surface acoustic wave resonator has a transverse mode due to the sound wave transversely transmitted by the surface acoustic wave resonator, or other resonant modes except a main acoustic mode are excited by the electrode finger strips, and the noise waves are reflected in and near the passband of the surface acoustic wave resonator, and can reduce the performance of the surface acoustic wave resonator.
How to improve the performance of the saw resonator is then a great issue in the design of the resonator today.
Disclosure of Invention
In view of the above, the present invention provides a surface acoustic wave resonator, a method for manufacturing the same, and a filter, wherein the method comprises the following steps:
A surface acoustic wave resonator, the surface acoustic wave resonator comprising:
a substrate;
an interdigital electrode positioned on one side of the substrate; the interdigital electrode comprises a bus bar, wherein the bus bar comprises a first bus bar and a second bus bar which are oppositely arranged in a first direction, and a first electrode finger strip positioned on the first bus bar and a second electrode finger strip positioned on the second bus bar; the length extension directions of the first bus bar and the second bus bar are the same, the first bus bar and the second bus bar extend along a second direction, the first direction and the second direction are parallel to the plane of the substrate, and the first direction and the second direction are intersected;
the dielectric layer is positioned on one side of the interdigital electrode, which is far away from the substrate, and the orthographic projection of the dielectric layer on the plane of the substrate at least completely covers the orthographic projection of the interdigital electrode on the plane of the substrate;
the heat conducting layer is positioned on one side of the dielectric layer, which is away from the substrate; the heat conduction layer is provided with a removal area, the removal area comprises a first groove area and a second groove area, the first groove area is positioned on one side of the first bus bar facing the second bus bar, the second groove area is positioned on one side of the second bus bar facing the first bus bar, the orthographic projection of the first groove area on the plane of the substrate at least covers the orthographic projection of the tail end area of the second electrode finger on the plane of the substrate and extends along the second direction, and the orthographic projection of the second groove area on the plane of the substrate at least covers the orthographic projection of the tail end area of the first electrode finger on the plane of the substrate and extends along the second direction.
Preferably, in the surface acoustic wave resonator, a width of the first groove region in the first direction ranges from 1λ to 1.5λ;
the width of the second groove region in the first direction ranges from 1 lambda to 1.5 lambda;
where λ represents the wavelength of the surface acoustic wave resonator.
Preferably, in the surface acoustic wave resonator, the heat conducting layer includes a first heat conducting layer;
the first groove region penetrates through the first heat conduction layer, and the second groove region penetrates through the first heat conduction layer.
Preferably, in the surface acoustic wave resonator, the material of the first heat conducting layer is an AlN material, a Si material, a SiC material, a diamond material, a quartz material, a sapphire material, or a SiN material.
Preferably, in the surface acoustic wave resonator, the heat conducting layer further includes:
and the second heat conduction layer is positioned on one side of the first heat conduction layer, which is away from the substrate.
Preferably, in the surface acoustic wave resonator, the material of the second heat conducting layer is SiN material.
Preferably, in the surface acoustic wave resonator, the first groove region penetrates through the first heat conductive layer and the second heat conductive layer at the same time, and the second groove region penetrates through the first heat conductive layer and the second heat conductive layer at the same time.
Preferably, in the surface acoustic wave resonator, the first groove region penetrates through the second heat conduction layer, and exposes a part of the surface of the first heat conduction layer; the second groove region penetrates through the second heat conduction layer, and part of the surface of the first heat conduction layer is exposed.
Preferably, in the above surface acoustic wave resonator, the surface acoustic wave resonator further includes:
and the plurality of first dummy electrode fingers are positioned on the first bus bar, the plurality of second dummy electrode fingers are positioned on the second bus bar, the length extension direction of the first dummy electrode fingers is parallel to the first direction, and the length extension direction of the second dummy electrode fingers is parallel to the first direction.
Preferably, in the surface acoustic wave resonator, the removing area of the heat conducting layer further includes a third groove area and a fourth groove area;
the third groove area is located between the first groove area and the first bus bar, the fourth groove area is located between the second groove area and the second bus bar, the orthographic projection of the third groove area on the plane where the substrate is located at least covers the orthographic projection of the first dummy electrode finger strip on the plane where the substrate is located, and extends along the second direction, and the orthographic projection of the fourth groove area on the plane where the substrate is located at least covers the orthographic projection of the second dummy electrode finger strip on the plane where the substrate is located, and extends along the second direction.
Preferably, in the surface acoustic wave resonator, a reflection grating is located at least one end of the interdigital electrode along the second direction;
the orthographic projection of the heat conducting layer on the plane of the substrate also covers the orthographic projection of the reflecting grating on the plane of the substrate.
Preferably, in the surface acoustic wave resonator, the removing area further extends to an area where the reflecting grating is located.
Preferably, in the surface acoustic wave resonator, a projected line of a boundary of the removed area of the heat conducting layer facing the bus bar is parallel to a target line, and the target line is a virtual line formed by connecting ends of the electrode fingers.
Preferably, in the surface acoustic wave resonator, a width of the removed region of the heat conductive layer in the first direction changes linearly, non-linearly, or stepwise along the second direction.
Preferably, in the surface acoustic wave resonator, a width of the removed region of the heat conductive layer in the first direction decreases and increases from one end to the other end of the interdigital electrode;
or alternatively, the first and second heat exchangers may be,
the width of the removal area of the heat conduction layer in the first direction increases and then decreases from one end of the interdigital electrode to the other end of the interdigital electrode.
The application also provides a preparation method of the surface acoustic wave resonator, which comprises the following steps:
providing a substrate;
forming interdigital electrodes on the substrate; the interdigital electrode comprises a bus bar, wherein the bus bar comprises a first bus bar and a second bus bar which are oppositely arranged in a first direction, and a first electrode finger strip positioned on the first bus bar and a second electrode finger strip positioned on the second bus bar; the length extension directions of the first bus bar and the second bus bar are the same, the first bus bar and the second bus bar extend along a second direction, the first direction and the second direction are parallel to the plane of the substrate, and the first direction and the second direction are intersected;
forming a dielectric layer on one side of the interdigital electrode, which is away from the substrate;
forming a heat conduction layer on one side of the dielectric layer, which is away from the substrate;
the heat conduction layer is subjected to graphic processing to form a removal area, the removal area comprises a first groove area and a second groove area, the first groove area is located on one side of the first bus bar facing the second bus bar, the second groove area is located on one side of the second bus bar facing the first bus bar, the orthographic projection of the first groove area on the plane of the substrate at least covers the orthographic projection of the tail end area of the second electrode finger on the plane of the substrate, and extends along the second direction, and the orthographic projection of the second groove area on the plane of the substrate at least covers the orthographic projection of the tail end area of the first electrode finger on the plane of the substrate, and extends along the second direction.
The application also provides a filter comprising the surface acoustic wave resonator according to any one of the above.
Compared with the prior art, the invention has the following beneficial effects:
according to the surface acoustic wave resonator, the preparation method and the filter thereof, at least one heat conducting layer is formed above the interdigital electrodes, and patterning processing is carried out on the heat conducting layer to remove part of the heat conducting layer, sound velocity is reduced in the removed area, so that the speed reduction is formed in a clearance area between specific interface positions (electrode finger strips and opposite bus strips or between electrode finger strips and false electrode finger strips), namely, the boundary of the area with the largest sound velocity, so that a larger sound velocity difference is obtained, a transverse mode is restrained through reflection clutter, the condition that the transverse mode forms resonance is destroyed, clutter is restrained, energy dissipation is avoided, and finally the performance of the surface acoustic wave resonator is improved. The heat conduction layer can also enable heat generated by the surface acoustic wave resonator to be more easily emitted to a certain extent, so that the maximum power tolerance effect of the surface acoustic wave resonator can be improved.
Drawings
In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings that are required to be used in the embodiments or the description of the prior art will be briefly described below, and it is obvious that the drawings in the following description are only embodiments of the present invention, and that other drawings can be obtained according to the provided drawings without inventive effort for a person skilled in the art.
Fig. 1 is a schematic cross-sectional structure of a surface acoustic wave resonator in the prior art;
FIG. 2 is a schematic cross-sectional view of another SAW resonator in the prior art;
fig. 3 is a schematic top view of a surface acoustic wave resonator according to an embodiment of the present invention;
fig. 4 is a schematic top view of another surface acoustic wave resonator according to an embodiment of the present invention;
fig. 5 is a schematic top view of a surface acoustic wave resonator according to an embodiment of the present invention;
fig. 6 is a schematic cross-sectional structure of a surface acoustic wave resonator according to an embodiment of the present invention;
fig. 7 is a schematic top view of a surface acoustic wave resonator according to an embodiment of the present invention;
fig. 8 is a schematic cross-sectional structure of another surface acoustic wave resonator according to an embodiment of the present invention;
fig. 9 is a schematic cross-sectional structure of a surface acoustic wave resonator according to another embodiment of the present invention;
fig. 10 is a schematic cross-sectional structure of a surface acoustic wave resonator according to another embodiment of the present invention;
FIG. 11 is a schematic diagram of sound velocity variation effect caused by removing a region according to an embodiment of the present invention;
FIG. 12 is a schematic view of sound velocity variation effects caused by another removal region according to an embodiment of the present invention;
Fig. 13 is a schematic top view of a surface acoustic wave resonator according to another embodiment of the present invention;
fig. 14 is a schematic top view of a surface acoustic wave resonator according to another embodiment of the present invention;
fig. 15 is a schematic top view of a surface acoustic wave resonator according to another embodiment of the present invention;
fig. 16 is a schematic top view of a surface acoustic wave resonator according to an embodiment of the present invention;
fig. 17 is a schematic top view of a surface acoustic wave resonator according to another embodiment of the present invention;
fig. 18 is a schematic top view of a surface acoustic wave resonator according to an embodiment of the present invention;
fig. 19 is a schematic top view of a surface acoustic wave resonator according to an embodiment of the present invention;
fig. 20 is a schematic top view of a surface acoustic wave resonator according to an embodiment of the present invention;
fig. 21 is a schematic top view of a surface acoustic wave resonator according to an embodiment of the present invention;
fig. 22 is a schematic top view of a surface acoustic wave resonator according to an embodiment of the present invention;
fig. 23 is a schematic top view of a surface acoustic wave resonator according to an embodiment of the present invention;
fig. 24 is a schematic top view of a surface acoustic wave resonator according to an embodiment of the present invention;
Fig. 25 is a schematic flow chart of a method for manufacturing a surface acoustic wave resonator according to an embodiment of the present invention.
Detailed Description
The following description of the embodiments of the present invention will be made clearly and completely with reference to the accompanying drawings, in which it is apparent that the embodiments described are only some embodiments of the present invention, but not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.
The surface acoustic wave resonator and the filter are acoustic devices widely applied to the radio frequency field, integrate low insertion loss and good inhibition performance, have smaller volume, are used for filtering interference of different-frequency signals, attenuate partial frequency components, only enable specified frequency components, and are the technical foundation of application of wireless frequency spectrum as nonrenewable scarce resources. The specific principle can be simply understood as that based on the piezoelectric characteristics of piezoelectric materials, the input and output transducer devices such as interdigital transducers are utilized to convert electric signals into mechanical energy, and the mechanical energy is converted into electric signals after being processed, so that the effects of amplifying required signals, filtering out impurity signals and improving signal quality are achieved, and the piezoelectric transducer is widely applied to various wireless communication equipment.
Currently, filters are largely classified into SAW filters and BAW (Bulk Acoustic Wave ) filters, in which a surface acoustic wave is an elastic wave that is generated and propagates on the surface of a piezoelectric substrate having piezoelectric characteristics, and whose amplitude decreases rapidly with increasing depth into the piezoelectric substrate. For the SAW filter, the manufacturing cost is much lower than that of the BAW filter, and the SAW filter is applied to a low frequency band, has low insertion loss, good inhibition and temperature sensitivity.
Meanwhile, it should be noted that the SAW filter has a corresponding limitation in that it is susceptible to temperature change, and when the temperature increases, the rigidity of the substrate material tends to decrease, and the sound velocity also decreases, so to speak, the SAW filter has a defect of temperature drift, i.e., the frequency drift with the operating temperature, so that based on the conventional SAW filter, a TC-SAW filter, i.e., a temperature compensated SAW filter, is correspondingly produced, mainly using a temperature compensation layer (e.g., siO 2 Layer) is opposite to the temperature elastic characteristic of the piezoelectric layer, and the compensation of the temperature drift characteristic is realized. Further, SAW filters, as well as TF thin film SAW filters, are designed, and the POI multilayer substrate often includes a Si substrate, a piezoelectric thin film layer, a temperature compensation layer, and other dielectric layers.
In which the filter is designed by using resonators as basic units, a corresponding topology can be constructed and the signal of the specified frequency component can be amplified.
For a TC-SAW resonator or a conventional SAW resonator or TF-SAW resonator, a transverse mode occurs in the SAW resonator due to an acoustic wave propagating transversely of the SAW resonator, or the electrode finger strips excite other resonant modes besides the primary acoustic mode, which are reflected in and near the passband of the SAW resonator, and the clutter can reduce the performance of the SAW resonator and increase energy dissipation.
Based on this, there are also some designs in the prior art to help suppress lateral spurious modes, such as for use with low acoustic speed materials, and the like.
Referring to fig. 1, fig. 1 is a schematic cross-sectional structure of a surface acoustic wave resonator in the prior art, in which a recess having a specific shape is formed in a piezoelectric material region under an interdigital electrode, and a low acoustic velocity material 10a is filled in the recess, so as to change the acoustic velocity of acoustic wave propagation to enhance the suppression effect on a transverse hetero-mode, but in the case of a TF-SAW resonator, the process thickness cannot allow a sound velocity changing portion to be provided in a substrate on the one hand, and the piezoelectric effect in the normal operation of the resonator can be affected on the other hand, so that this prior art is not practical.
Referring to fig. 2, fig. 2 is a schematic cross-sectional structure of another surface acoustic wave resonator in the prior art, in which an interposer 10b is disposed in a dielectric material above an interdigital electrode, and is particularly suitable for use in a TC-SAW resonator; but it is not practical in some situations because it causes the process to become more complex and has an effect on the thickness of the resonator.
In addition, SAW resonators cannot be used in higher power environments, and therefore, there is a need for a solution to the problem of improving the power tolerance of SAW resonators.
Based on this, the embodiment of the invention provides a surface acoustic wave resonator, a preparation method thereof and a filter, at least one layer of heat conducting layer is formed above an interdigital electrode, and patterning processing is carried out on the heat conducting layer to remove part of the heat conducting layer, so that sound velocity is reduced in a removed area, and a speed reduction is formed in a clearance area between specific interface positions (an electrode finger strip and a counter bus bar or an electrode finger strip and a false electrode finger strip), namely, the boundary of the area with the largest sound velocity, so as to obtain a larger sound velocity difference, thereby inhibiting a transverse mode by reflecting clutter, and further reflecting the transverse mode in different directions by optimizing the change of the width of the removed area in the propagation direction of a main acoustic mode, such as a weighted gradual change mode and the like, so as to destroy the condition of resonance formation of the heat conducting layer, thereby inhibiting clutter, avoiding energy dissipation and finally improving the performance of the surface acoustic wave resonator. The heat conduction layer can also enable heat generated by the surface acoustic wave resonator to be more easily emitted to a certain extent, so that the maximum power tolerance effect of the surface acoustic wave resonator can be improved.
It should be noted that, the SAW resonator provided by the embodiment of the present invention includes, but is not limited to, a common SAW resonator, a TC-SAW resonator, or a TF-SAW resonator, that is, the technical solution provided by the embodiment of the present invention may be applied to a common SAW resonator, a TC-SAW resonator, or a TF-SAW resonator, but in the embodiment of the present invention, the TC-SAW resonator is merely modified to be a main solution, and when the technical solution of the present invention is applied to a common SAW resonator and a TF-SAW resonator, only the temperature compensation layer needs to be replaced by another dielectric layer, or a thicker heat conducting layer is used to avoid additional influence on lateral mode suppression.
In order that the above-recited objects, features and advantages of the present invention will become more readily apparent, a more particular description of the invention will be rendered by reference to the appended drawings and appended detailed description.
Referring to fig. 3, fig. 3 is a schematic top view of a surface acoustic wave resonator according to an embodiment of the present invention, and referring to fig. 4, fig. 4 is a schematic top view of another surface acoustic wave resonator according to an embodiment of the present invention, where the surface acoustic wave resonator according to the embodiment of the present invention includes:
the substrate 11, the substrate 11 can be a piezoelectric substrate or a substrate with a piezoelectric film.
An interdigital electrode 12 located on one side of the substrate 11; wherein the interdigital electrode 12 includes a bus bar including a first bus bar 121 and a second bus bar 122 disposed opposite in a first direction X, and a first electrode finger 123 on the first bus bar 121 and a second electrode finger 124 on the second bus bar 122; the length extension directions of the first bus bar 121 and the second bus bar 122 are the same, and the first bus bar and the second bus bar extend along a second direction Y, wherein the first direction X and the second direction Y are parallel to a plane of the substrate, and the first direction X and the second direction Y are intersected; the first direction X and the second direction Y are illustrated as being perpendicular as shown in fig. 3, and the first direction X and the second direction Y are illustrated as not intersecting perpendicularly as shown in fig. 4, that is, the interdigital electrode 12 shown in fig. 4 is of an oblique design.
The improvement in the technical solution of the present invention is applicable to the surface acoustic wave resonator shown in fig. 3, and is also applicable to the surface acoustic wave resonator shown in fig. 4, and in the following embodiments of the present invention, only the surface acoustic wave resonator shown in fig. 3 is taken as an example for illustration.
The length extending directions of the first electrode finger strips 123 and the second electrode finger strips 124 are the same, and are respectively parallel to the first direction X, the first electrode finger strips 123 on the first bus bar 121 are arranged at intervals in the second direction Y, the second electrode finger strips 124 on the second bus bar 122 are arranged at intervals in the second direction Y, the first electrode finger strips 123 on the first bus bar 121 and the second electrode finger strips 124 on the second bus bar 122 are sequentially and crosswise arranged in the second direction Y, and intervals are arranged between the first electrode finger strips 123 and the second bus bar 122 on the first bus bar 121, and the second electrode finger strips 124 on the second bus bar 122 and the first bus bar 121 are arranged at intervals, and the bus bars and the electrode finger strips are distributed in a similar finger crossing manner to form a so-called interdigital electrode. When the first bus bar 121 and the first electrode finger 123 thereon are used as the transmitting end, the second bus bar 122 and the second electrode finger 124 thereon are used as the receiving end, whereas when the first bus bar 121 and the first electrode finger 123 thereon are used as the receiving end, the second bus bar 122 and the second electrode finger 124 thereon are used as the transmitting end. The transmitting end part is used for converting the electric signal into sound waves, the sound waves mainly propagate on the surface of the substrate, and the receiving end part is used for converting the received sound waves into electric signal output, so that filtering is realized.
Referring to fig. 5, fig. 5 is a schematic top view of a surface acoustic wave resonator according to an embodiment of the present invention, referring to fig. 6, fig. 6 is a schematic cross-sectional structure of a surface acoustic wave resonator according to an embodiment of the present invention, and as shown in fig. 5 and fig. 6, the surface acoustic wave resonator according to an embodiment of the present invention further includes:
the dielectric layer 13 is positioned on the side of the interdigital electrode 12 away from the substrate 11, and the orthographic projection of the dielectric layer 13 on the plane of the substrate 11 at least completely covers the orthographic projection of the interdigital electrode 12 on the plane of the substrate 11.
When the acoustic surface resonator provided by the embodiment of the present invention is a TC-SAW resonator, the dielectric layer 13 may be a temperature compensation layer, and when the acoustic surface resonator provided by the embodiment of the present invention is a normal SAW resonator or a TF-SAW resonator, the dielectric layer 13 may be a dielectric layer corresponding to the normal SAW resonator or the TF-SAW resonator.
Alternatively, the material of the temperature compensation layer may be SiO 2 The thickness of the temperature compensation layer is greater than that of the underlying metal layer, and it is also understood that the thickness of the temperature compensation layer is greater than that of the interdigital electrode 12, and the thickness of the temperature compensation layer ranges from 0.2λ to 0.5λ, where λ represents the wavelength of the surface acoustic wave resonator.
That is, in the embodiment of the present invention, for the TC-SAW resonator, a temperature compensation layer is deposited in the aperture area (i.e. the area where the interdigital electrode 12 is located) of the SAW resonator, and the surface of the side of the temperature compensation layer facing away from the substrate 11 is polished to be flat, the temperature compensation layer is compact in structure, so as to compensate the negative temperature effect of the SAW resonator, especially on some chamfer substrates (such as 128 ° YXLiNb 03), the SiO 2 The temperature compensation layer of the material can effectively inhibit the transverse shear wave mode excited by the electrode finger.
In fig. 5, the coverage area of the dielectric layer 13 is different from the coverage area of the substrate 11, and in some alternative embodiments, the coverage area of the dielectric layer 13 and the coverage area of the substrate 11 may be the same, in order to better represent the layer relationship.
Referring to fig. 7, fig. 7 is a schematic top view of a surface acoustic wave resonator according to an embodiment of the present invention, and referring to fig. 8, fig. 8 is a schematic cross-sectional structure of another surface acoustic wave resonator according to an embodiment of the present invention, where, as shown in fig. 7 and fig. 8, the surface acoustic wave resonator according to an embodiment of the present invention further includes:
And the heat conducting layer 14 is positioned on one side of the dielectric layer 13 away from the substrate 11.
The heat conducting layer 14 has a removing area, the removing area includes a first groove area 141 and a second groove area 142, the first groove area 141 is located at a side of the first bus bar 121 facing the second bus bar 122, the second groove area 142 is located at a side of the second bus bar 122 facing the first bus bar 121, the length extending directions of the first groove area 141 and the second groove area 142 are the same, and are parallel to the second direction Y, respectively, the front projection of the first groove area 141 on the plane of the substrate 11 at least covers the front projection of the end area of the second electrode finger 124 on the plane of the substrate 11, and extends along the second direction Y, the front projection of the second groove area 142 on the plane of the substrate 11 at least covers the front projection of the end area of the first electrode finger 123 on the plane of the substrate 11, and extends along the second direction Y.
In fig. 7, the coverage area of the dielectric layer 13, the coverage area of the substrate 11, and the coverage area of the heat conductive layer 14 are different from each other, and in some alternative embodiments, the coverage area of the dielectric layer 13, the coverage area of the substrate 11, and the coverage area of the heat conductive layer 14 may be the same.
Specifically, in the embodiment of the present invention, a gap area is formed between the first electrode finger 123 and the opposite second bus bar 122, a gap area is also formed between the second electrode finger 124 and the opposite first bus bar 121, the heat conducting layer 14 is patterned to form a first groove area 141 and a second groove area 142, so that the orthographic projection of the first groove area 141 on the plane of the substrate 11 covers at least the orthographic projection of the end area of the second electrode finger 124 on the plane of the substrate 11, and extends along the second direction Y, so that the orthographic projection of the second groove area 142 on the plane of the substrate 11 covers at least the orthographic projection of the end area of the first electrode finger 123 on the plane of the substrate 11, and extends along the second direction Y. The heat conduction layer can also enable heat generated by the surface acoustic wave resonator to be more easily emitted to a certain extent, so that the maximum power tolerance effect of the surface acoustic wave resonator can be improved.
Alternatively, in another embodiment of the present invention, the width of the first groove region 141 in the first direction X ranges from 1λ to 1.5λ.
The second groove region 142 has a width in the first direction X ranging from 1λ to 1.5λ.
Alternatively, in another embodiment of the present invention, as shown in fig. 8, the heat conductive layer 14 provided in the embodiment of the present invention includes a first heat conductive layer 14a.
Specifically, in the embodiment of the present invention, the heat conductive layer 14 only includes a heat conductive layer structure, and the material of the first heat conductive layer 14a includes, but is not limited to, alN material, si material, siC material, diamond material, quartz material, sapphire material, siN material, or the like.
Alternatively, in another embodiment of the present invention, the thickness of the first heat conductive layer 14a is greater than 40nm.
Specifically, in the embodiment of the present invention, the first heat-conducting layer 14a of AlN material is taken as an example, when the surface acoustic wave resonator is a TC-SAW resonator, the thickness of the temperature compensation layer needs to be determined according to the wavelength and the thickness of the piezoelectric layer, so in the conventional temperature compensation layer thickness range, the applicant finds that when the thickness of the first heat-conducting layer 14a of AlN material is greater than 40nm, the maximum temperature drop of the surface acoustic wave resonator will enter a relatively gentle range, that is, when the thickness of the first heat-conducting layer 14a of AlN material is less than 40nm, the maximum temperature of the surface acoustic wave resonator will change very rapidly when the thickness of the first heat-conducting layer 14a of AlN material is thickened, that is, the effect of increasing the maximum power tolerance of the surface acoustic wave resonator by thickening the thickness of the first heat-conducting layer 14a of AlN material will be very obvious, and when the thickness of the first heat-conducting layer 14a of AlN material is thickened at this time is greater than 40nm, the effect of increasing the maximum power tolerance of the surface acoustic wave resonator will not be set to be the same as the first heat-conducting layer of the invention.
Optionally, in another embodiment of the present invention, referring to fig. 9, fig. 9 is a schematic cross-sectional structure of another surface acoustic wave resonator provided in an embodiment of the present invention, where the heat conducting layer provided in the embodiment of the present invention further includes:
and a second heat conductive layer 14b located on a side of the first heat conductive layer 14a facing away from the substrate 11.
Specifically, in the embodiment of the present invention, the material of the second heat conducting layer 14b includes, but is not limited to, siN material, and the second heat conducting layer 14b of SiN material also has a better passivation effect, because when the material of the first heat conducting layer 14a is AlN material, the AlN material has a stronger water absorption property, and is easy to absorb water molecules in air to affect the performance and quality of the device, so in the embodiment of the present invention, the second heat conducting layer 14b of SiN material is further formed, which can have both passivation effect and heat conducting effect.
Alternatively, in another embodiment of the present invention, as shown in fig. 8, when the heat conductive layer 14 only includes one first heat conductive layer 14a, the first groove region 141 penetrates the first heat conductive layer 14a, and the second groove region 142 also penetrates the first heat conductive layer 14a.
As shown in fig. 9, when the heat conductive layer 14 includes two heat conductive layers, that is, the heat conductive layer 14 includes the first heat conductive layer 14a and the second heat conductive layer 14b, the first groove region 141 penetrates through the first heat conductive layer 14a and the second heat conductive layer 14b at the same time, and the second groove region 142 also penetrates through the first heat conductive layer 14a and the second heat conductive layer 14b at the same time.
Referring to fig. 10, fig. 10 is a schematic cross-sectional structure of still another saw resonator according to an embodiment of the present invention, where the heat conducting layer 14 includes two heat conducting layers, that is, the heat conducting layer 14 includes a first heat conducting layer 14a and a second heat conducting layer 14b, the first groove region 141 only penetrates the second heat conducting layer 14b, and the second groove region 142 also only penetrates the second heat conducting layer 14b.
That is, in the embodiment of the present invention, based on the arrangement manner of the different heat conductive layers 14, the corresponding region of at least one heat conductive layer should be removed to form the first groove region 141 and the second groove region 142, and it should be noted that when the heat conductive layer 14 includes two heat conductive layers and only the corresponding region of one heat conductive layer is removed, only the corresponding region of the second heat conductive layer 14b can be removed to form the first groove region 141 and the second groove region 142.
Referring to fig. 11, fig. 11 is a schematic view of the sound velocity change effect caused by the removal region according to the embodiment of the present invention, referring to fig. 12, fig. 12 is a schematic view of the sound velocity change effect caused by the removal region according to the embodiment of the present invention, and when the heat conducting layer 14 includes two heat conducting layers, that is, when the heat conducting layer 14 includes the first heat conducting layer 14a and the second heat conducting layer 14b, the first groove region 141 only penetrates the second heat conducting layer 14b, and the second groove region 142 also only penetrates the second heat conducting layer 14b, as shown in fig. 12, the heat conducting layer 14 includes only one first heat conducting layer 14a, the first groove region 141 penetrates the first heat conducting layer 14a, and the second groove region 142 also penetrates the first heat conducting layer 14a, and as shown in fig. 11 and 12, it is known that when the removal region only penetrates the second heat conducting layer, a larger sound velocity difference is easily obtained.
Optionally, in another embodiment of the present invention, referring to fig. 13, fig. 13 is a schematic top view structure of another surface acoustic wave resonator provided in an embodiment of the present invention, where the surface acoustic wave resonator provided in the embodiment of the present invention further includes:
the first dummy electrode fingers 125 and the second dummy electrode fingers 126 are arranged on the first bus bar 121, the second dummy electrode fingers 126 are arranged on the second bus bar 122, the length extending direction of the dummy electrode fingers is parallel to the first direction X, the first dummy electrode fingers 125 and the first electrode fingers 123 are arranged on the first bus bar 121 at intervals in the second direction Y, the second dummy electrode fingers 126 and the second electrode fingers 124 are arranged on the second bus bar 122 at intervals in the second direction Y, the first electrode fingers 123 on the first bus bar 121 and the second dummy electrode fingers 126 on the second bus bar 122 are arranged opposite to each other with intervals therebetween, and the first dummy electrode fingers 125 on the first bus bar 121 and the second electrode fingers 124 on the second bus bar 122 are arranged opposite to each other with intervals therebetween.
That is, in the embodiment of the present invention, the interdigital electrode 12 may be an interdigital electrode without a dummy electrode finger, or an interdigital electrode with a dummy electrode finger as shown in fig. 13, and when the interdigital electrode 12 is provided with a dummy electrode finger, the provision of a dummy electrode finger also has the effect of suppressing noise and improving the quality factor of the surface acoustic wave resonator.
Specifically, in the embodiment of the present invention, when the interdigital electrode 12 is provided with the dummy electrode finger, a gap area is formed between the first electrode finger 123 and the opposite second dummy electrode finger 126, and a gap area is also formed between the second electrode finger 124 and the opposite first dummy electrode finger 125, at this time, as shown in fig. 13, the first groove area 141 and the second groove area 142 may be formed by performing patterning processing on the heat conducting layer 14, so that the front projection of the first groove area 141 on the plane of the substrate 11 covers at least the front projection of the end area of the second electrode finger 124 on the plane of the substrate 11, and extends along the second direction Y, so that the front projection of the second groove area 142 on the plane of the substrate 11 covers at least the front projection of the end area of the first electrode finger 123 on the plane of the substrate 11, and extends along the second direction Y.
Optionally, in another embodiment of the present invention, referring to fig. 14, fig. 14 is a schematic top view structure of a surface acoustic wave resonator provided in the embodiment of the present invention, where the removed area of the heat conducting layer 14 further includes a third groove area 143 and a fourth groove area 144, the third groove area 143 is located between the first groove area 141 and the first bus bar 121, the fourth groove area 144 is located between the second groove area 142 and the second bus bar 122, the lengths of the third groove area 143 and the fourth groove area 144 extend in the same direction as the second direction Y, and the orthographic projection of the third groove area 143 on the plane of the substrate 11 at least covers the orthographic projection of the first dummy electrode finger 125 on the plane of the substrate 11 and extends along the second direction Y, and the orthographic projection of the fourth groove area 144 on the plane of the substrate 11 at least covers the orthographic projection of the second dummy electrode finger 126 on the plane of the substrate 11 and extends along the second direction Y.
Specifically, when the interdigital electrode 12 is provided with the dummy electrode finger strips, a gap area is formed between the first electrode finger strip 123 and the opposite second dummy electrode finger strip 126, and a gap area is also formed between the second electrode finger strip 124 and the opposite first dummy electrode finger strip 125, at this time, as shown in fig. 14, the heat conducting layer 14 may be patterned to form a first groove area 141, a second groove area 142, a third groove area 143 and a fourth groove area 144, so that the front projection of the first groove area 141 on the plane of the substrate 11 at least covers the front projection of the end area of the second electrode finger strip 124 on the plane of the substrate 11, and extends along the second direction Y, so that the front projection of the second groove area 142 on the plane of the substrate 11 at least covers the front projection of the end area of the first electrode finger strip 123 on the plane of the substrate 11, and extends in the second direction Y so that the orthographic projection of the third groove region 143 on the plane of the substrate 11 at least covers the orthographic projection of the first dummy electrode finger 125 on the plane of the substrate 11, and extends in the second direction Y so that the orthographic projection of the fourth groove region 144 on the plane of the substrate 11 at least covers the orthographic projection of the second dummy electrode finger 126 on the plane of the substrate 11, and extends in the second direction Y, this design corresponds to forming the removal regions of the heat conductive layer 14 on both sides of the gap region between the electrode finger and the opposing dummy electrode finger, respectively, reducing the sound velocity in the removal regions by using the removed portions of the high sound velocity material, thereby reducing the sound velocity in the gap region between the electrode finger and the opposing dummy electrode finger at a specific interface position (this specific interface position is the gap region between the electrode finger and the opposing dummy electrode finger), that is, the boundary of the region where the sound velocity is the largest forms a deceleration to obtain a larger sound velocity difference, so that the transverse mode is suppressed by reflecting the clutter, thereby improving the performance of the surface acoustic wave resonator.
Optionally, in another embodiment of the present invention, referring to fig. 15, fig. 15 is a schematic top view structure of another surface acoustic wave resonator provided by an embodiment of the present invention, referring to fig. 16, fig. 16 is a schematic top view structure of another surface acoustic wave resonator provided by an embodiment of the present invention, where the surface acoustic wave resonator provided by the embodiment of the present invention further includes:
the reflective grating 15 located at least one end of the interdigital electrode 12 along the second direction Y is described by taking, as an example, that the reflective grating 15 is disposed at each end of the interdigital electrode 12 along the second direction Y in the embodiment of the present invention.
Specifically, in the embodiment of the present invention, a reflective grating 15 may be further disposed at least one end of the interdigital electrode 12 along the second direction Y, so as to reflect the sound wave back to the resonance area, so that the sound wave continues to form resonance in the resonance area, thereby forming better resonance effect and mode, and improving the transmission performance of the surface acoustic wave resonator.
When the surface acoustic wave resonator provided by the embodiment of the present invention includes the reflection grating, as shown in fig. 15, the first groove region 141 and the second groove region 142 do not extend to the region where the reflection grating 15 is located; as shown in fig. 16, the first groove area 141 and the second groove area 142 further extend to the area where the reflective grating 15 is located, that is, the removing area further extends to the area where the reflective grating is located, which is not limited in the embodiment of the present invention, and may be reasonably designed according to practical situations.
Optionally, in another embodiment of the present invention, when the saw resonator provided in the embodiment of the present invention includes both the dummy electrode finger and the reflection grating 15, the first groove region 141, the second groove region 142, the third groove region 143, and the fourth groove region 144 do not extend to the region where the reflection grating 15 is located; or the first groove region 141, the second groove region 142, the third groove region 143 and the fourth groove region 144 also extend to the region where the reflective grid 15 is located.
It is obvious that in some alternative embodiments, the solution with the reflective grating 15 and the solution with the dummy electrode fingers may be flexibly combined, for example, the first groove region 141 and the second groove region 142 do not extend to the area where the reflective grating 15 is located, and the third groove region 143 and the fourth groove region 144 also extend to the area where the reflective grating 15 is located. It should be noted that other flexible combinations are not listed here.
Alternatively, in another embodiment of the present invention, the width of the removed area of the heat conducting layer 14 in the first direction X is changed in a weighted manner along the second direction Y, and the changing manner may be a linear change or a nonlinear change or a step change.
Specifically, in the embodiment of the present invention, the width of the removed area of the heat conducting layer 14 in the first direction X is changed in a weighted manner along the aperture direction, but it should be noted that the width range is required to be within the range of 1λ -1.5λ no matter how the width is changed. Referring to fig. 17, fig. 17 is a schematic top view of a surface acoustic wave resonator according to an embodiment of the present invention, and referring to fig. 18, fig. 18 is a schematic top view of a surface acoustic wave resonator according to an embodiment of the present invention, in which the widths of the first groove region 141 and the second groove region 142 in the first direction X change linearly along the second direction Y, and decrease and increase in the direction from one end to the other end of the interdigital electrode 12. Referring to fig. 19, fig. 19 is a schematic top view of a surface acoustic wave resonator according to an embodiment of the present invention, and referring to fig. 20, fig. 20 is a schematic top view of a surface acoustic wave resonator according to an embodiment of the present invention, in which widths of a first groove region 141 and a second groove region 142 in a first direction X linearly change along a second direction Y, and increase and decrease from one end to the other end of an interdigital electrode 12.
As shown in fig. 17 to 20, when the width of the removed area of the heat conductive layer 14 in the first direction X is linearly changed along the second direction Y, the projected lines of the boundary between the first groove area 141 and the second groove area 142 may be in the shape of a broken line.
Referring to fig. 21, fig. 21 is a schematic top view structure of a surface acoustic wave resonator according to an embodiment of the present invention, in which the widths of the first groove region 141 and the second groove region 142 in the first direction X vary non-linearly along the second direction Y, and the widths of the removed regions of the heat conductive layer 14 in the first direction Y decrease and increase from one end to the other end of the interdigital electrode 12, as shown in fig. 21, when the widths of the heat conductive layer between the first groove region 141 and the second groove region 142 vary non-linearly along the second direction Y, the projected lines of the boundary on both sides in the first direction X may be arc-shaped.
Referring to fig. 22, fig. 22 is a schematic top view structure of a surface acoustic wave resonator according to an embodiment of the present invention, in which the widths of the first groove region 141 and the second groove region 142 in the first direction X are changed stepwise along the second direction Y, and the widths of the removed region of the heat conductive layer 14 in the first direction X are reduced and increased in the direction from one end to the other end of the interdigital electrode 12, as shown in fig. 22, when the widths of the heat conductive layer between the first groove region 141 and the second groove region 142 in the first direction Y are changed non-stepwise along the second direction Y, the projected lines of the boundary on both sides in the first direction may be stepped.
Wherein the variation in width of the removed area of the heat conductive layer 14 in the first direction X shown in fig. 17, 19, 21 and 22 along the second direction Y is uniform and symmetrical; the variation in width of the removed area of the heat conductive layer 14 in the first direction X as shown in fig. 18 and 20 along the second direction Y is uneven and asymmetric.
In general, the width of the removed area of the heat conductive layer 14 in the first direction X may be uniform or non-uniform, symmetrical or asymmetrical, linear or nonlinear, stepped, etc. according to the actual situation, and the embodiment of the present invention is not limited thereto.
Alternatively, in another embodiment of the present invention, the projected line of the boundary of the removed area of the heat conducting layer 14 facing the bus bar is parallel to the target line, where the target line is a virtual line formed by connecting the ends of the electrode fingers.
As shown in fig. 17-22, since the electrode finger and the opposite bus bar have equal intervals, that is, the virtual line formed by connecting the ends of the electrode finger is a straight line and is disposed horizontally, the projected line of the boundary of the removed area of the heat conducting layer 14 facing the bus bar is also a straight line and also needs to be disposed horizontally, and the two lines are parallel to each other.
Referring to fig. 23, fig. 23 is a schematic top view structure of another saw resonator according to an embodiment of the present invention, in which the electrode finger and the opposite bus bar have equal intervals, that is, the virtual line formed by connecting the ends of the electrode finger is a straight line, but is inclined, so that the projected line of the boundary of the removed area of the heat conducting layer 14 facing the bus bar is also a straight line, and also needs to be inclined, and the two lines are parallel to each other.
Referring to fig. 24, fig. 24 is a schematic top view of another saw resonator according to an embodiment of the present invention, in which virtual lines formed by connecting ends of electrode fingers are broken lines, so that projected lines of a boundary of a removed area of the heat conducting layer 14 facing a bus bar side are broken lines, and the two projected lines are parallel to each other.
That is, in some special designs, the envelope formed by connecting the bus bars or the electrode finger tips may be a gradient structure such as an oblique or a zigzag, and the removed area should be correspondingly changed along with the boundary of the area, and meanwhile, the weighted gradient in the aperture direction may be further formed in the technology, so that the condition is unchanged and will not be described herein.
Based on the foregoing embodiments of the present invention, in another embodiment of the present invention, a method for manufacturing a surface acoustic wave resonator is further provided, and referring to fig. 25, fig. 25 is a schematic flow chart of a method for manufacturing a surface acoustic wave resonator according to an embodiment of the present invention, where the method for manufacturing a surface acoustic wave resonator according to an embodiment of the present invention includes:
S101: a substrate 11 is provided.
Specifically, the substrate 11 in this step may be a piezoelectric substrate or a substrate with a piezoelectric thin film.
S102: forming interdigital electrodes 12 on a substrate 11; wherein the interdigital electrode 12 includes a bus bar including a first bus bar 121 and a second bus bar 122 disposed opposite in a first direction X, and a first electrode finger 123 on the first bus bar 121 and a second electrode finger 124 on the second bus bar 122; the length extension directions of the first bus bar 121 and the second bus bar 122 are the same, and both extend along the second direction Y, the first direction X and the second direction Y are parallel to the plane of the substrate 11, and the first direction X and the second direction Y intersect.
S103: a dielectric layer 13 is formed on the side of the interdigital electrode 12 facing away from the substrate 11.
Specifically, in this step, the orthographic projection of the dielectric layer 13 on the plane of the substrate 11 at least completely covers the orthographic projection of the interdigital electrode 12 on the plane of the substrate 11. When the acoustic surface resonator provided by the embodiment of the present invention is a TC-SAW resonator, the dielectric layer 13 may be a temperature compensation layer, and when the acoustic surface resonator provided by the embodiment of the present invention is a normal SAW resonator or a TF-SAW resonator, the dielectric layer 13 may be a dielectric layer corresponding to the normal SAW resonator or the TF-SAW resonator.
S104: a thermally conductive layer 14 is formed on the side of the dielectric layer 13 facing away from the substrate 11.
S105, performing patterning treatment on the heat conducting layer 14 to make the heat conducting layer 14 have a removal area, where the removal area includes a first groove area 141 and a second groove area 142, the first groove area 141 is located at a side of the first bus bar 121 facing the second bus bar 122, the second groove area 142 is located at a side of the second bus bar 122 facing the first bus bar 121, the length extension directions of the first groove area 141 and the second groove area 142 are the same, and are respectively parallel to the second direction Y, and the front projection of the first groove area 141 on the plane of the substrate 11 at least covers the front projection of the end area of the second electrode finger 124 on the plane of the substrate 11, and extends along the second direction Y, and the front projection of the second groove area 142 on the plane of the substrate 11 at least covers the front projection of the end area of the first electrode finger 123 on the plane of the substrate 11, and extends along the second direction Y.
Specifically, in the surface acoustic wave resonator manufactured by the above manufacturing method in the embodiment of the present invention, a gap area is formed between the first electrode finger 123 and the opposite second bus bar 122, a gap area is also formed between the second electrode finger 124 and the opposite first bus bar 121, the heat conducting layer 14 is patterned to form the first groove area 141 and the second groove area 142, the front projection of the first groove area 141 on the plane of the substrate 11 covers at least the front projection of the end area of the second electrode finger 124 on the plane of the substrate 11, and extends along the second direction Y, the front projection of the second groove area 142 on the plane of the substrate 11 covers at least the front projection of the end area of the first electrode finger 123 on the plane of the substrate 11, and extends along the second direction Y. The heat conducting layer 14 can also make the heat generated by the surface acoustic wave resonator more easily dissipated to a certain extent, so that the maximum power tolerance effect of the surface acoustic wave resonator can be improved.
Optionally, according to the foregoing embodiment of the present invention, in another embodiment of the present invention, there is further provided a filter, which includes the surface acoustic wave resonator described in the foregoing embodiment.
The filter has the same effect as the surface acoustic wave resonator in the above embodiment.
The above description of the surface acoustic wave resonator, the preparation method thereof and the filter provided by the invention applies specific examples to illustrate the principle and the implementation of the invention, and the above examples are only used for helping to understand the method and the core idea of the invention; meanwhile, as those skilled in the art will have variations in the specific embodiments and application scope in accordance with the ideas of the present invention, the present description should not be construed as limiting the present invention in view of the above.
It should be noted that, in the present specification, each embodiment is described in a progressive manner, and each embodiment is mainly described as different from other embodiments, and identical and similar parts between the embodiments are all enough to be referred to each other. For the device disclosed in the embodiment, since it corresponds to the method disclosed in the embodiment, the description is relatively simple, and the relevant points refer to the description of the method section.
It is further noted that relational terms such as first and second, and the like are used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Moreover, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include, or is intended to include, elements inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising one … …" does not exclude the presence of other like elements in a process, method, article, or apparatus that comprises the element.
The previous description of the disclosed embodiments is provided to enable any person skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the invention. Thus, the present invention is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.
Claims (17)
1. A surface acoustic wave resonator, characterized in that the surface acoustic wave resonator comprises:
a substrate;
an interdigital electrode positioned on one side of the substrate; the interdigital electrode comprises a bus bar, wherein the bus bar comprises a first bus bar and a second bus bar which are oppositely arranged in a first direction, and a first electrode finger strip positioned on the first bus bar and a second electrode finger strip positioned on the second bus bar; the length extension directions of the first bus bar and the second bus bar are the same, the first bus bar and the second bus bar extend along a second direction, the first direction and the second direction are parallel to the plane of the substrate, and the first direction and the second direction are intersected;
the dielectric layer is positioned on one side of the interdigital electrode, which is far away from the substrate, and the orthographic projection of the dielectric layer on the plane of the substrate at least completely covers the orthographic projection of the interdigital electrode on the plane of the substrate;
the heat conducting layer is positioned on one side of the dielectric layer, which is away from the substrate; the heat conduction layer is provided with a removal area, the removal area comprises a first groove area and a second groove area, the first groove area is positioned on one side of the first bus bar facing the second bus bar, the second groove area is positioned on one side of the second bus bar facing the first bus bar, the orthographic projection of the first groove area on the plane of the substrate at least covers the orthographic projection of the tail end area of the second electrode finger on the plane of the substrate and extends along the second direction, and the orthographic projection of the second groove area on the plane of the substrate at least covers the orthographic projection of the tail end area of the first electrode finger on the plane of the substrate and extends along the second direction.
2. The surface acoustic wave resonator according to claim 1, characterized in that the width of the first groove region in the first direction ranges from 1λ to 1.5λ;
the width of the second groove region in the first direction ranges from 1 lambda to 1.5 lambda;
where λ represents the wavelength of the surface acoustic wave resonator.
3. The surface acoustic wave resonator of claim 1, wherein the thermally conductive layer comprises a first thermally conductive layer;
the first groove region penetrates through the first heat conduction layer, and the second groove region penetrates through the first heat conduction layer.
4. The surface acoustic wave resonator according to claim 3, characterized in that the material of the first heat conductive layer is an AlN material, a Si material, a SiC material, a diamond material, a quartz material, a sapphire material, or a SiN material.
5. The surface acoustic wave resonator according to claim 3, characterized in that the heat conductive layer further comprises:
and the second heat conduction layer is positioned on one side of the first heat conduction layer, which is away from the substrate.
6. The surface acoustic wave resonator according to claim 5, characterized in that the material of the second heat conducting layer is SiN material.
7. The surface acoustic wave resonator of claim 5, wherein the first groove region extends through both the first thermally conductive layer and the second thermally conductive layer, and the second groove region extends through both the first thermally conductive layer and the second thermally conductive layer.
8. The surface acoustic wave resonator of claim 5, wherein the first groove region penetrates the second thermally conductive layer exposing a portion of a surface of the first thermally conductive layer; the second groove region penetrates through the second heat conduction layer, and part of the surface of the first heat conduction layer is exposed.
9. The surface acoustic wave resonator according to claim 1, characterized in that it further comprises:
and the plurality of first dummy electrode fingers are positioned on the first bus bar, the plurality of second dummy electrode fingers are positioned on the second bus bar, the length extension direction of the first dummy electrode fingers is parallel to the first direction, and the length extension direction of the second dummy electrode fingers is parallel to the first direction.
10. The surface acoustic wave resonator according to claim 9, characterized in that the removed area of the heat conductive layer further comprises a third groove area and a fourth groove area;
the third groove area is located between the first groove area and the first bus bar, the fourth groove area is located between the second groove area and the second bus bar, the orthographic projection of the third groove area on the plane where the substrate is located at least covers the orthographic projection of the first dummy electrode finger strip on the plane where the substrate is located, and extends along the second direction, and the orthographic projection of the fourth groove area on the plane where the substrate is located at least covers the orthographic projection of the second dummy electrode finger strip on the plane where the substrate is located, and extends along the second direction.
11. The surface acoustic wave resonator according to claim 1, characterized by a reflective grating located at least one end of the interdigital electrode in the second direction;
the orthographic projection of the heat conducting layer on the plane of the substrate also covers the orthographic projection of the reflecting grating on the plane of the substrate.
12. The saw resonator of claim 11, wherein the removed area further extends to the area where the reflective grating is located.
13. The surface acoustic wave resonator according to claim 1, wherein a projected line of a boundary of the removed area of the heat conductive layer facing the bus bar side is parallel to a target line, and the target line is a virtual line formed by connecting ends of the electrode fingers.
14. The surface acoustic wave resonator according to any of claims 1-13, characterized in that the width of the removed area of the heat conducting layer in the first direction varies linearly, non-linearly or stepwise along the second direction.
15. The surface acoustic wave resonator according to claim 14, characterized in that the width of the removed area of the heat conductive layer in the first direction decreases and increases from one end to the other end of the interdigital electrode;
Or alternatively, the first and second heat exchangers may be,
the width of the removal area of the heat conduction layer in the first direction increases and then decreases from one end of the interdigital electrode to the other end of the interdigital electrode.
16. The preparation method of the surface acoustic wave resonator is characterized by comprising the following steps of:
providing a substrate;
forming interdigital electrodes on the substrate; the interdigital electrode comprises a bus bar, wherein the bus bar comprises a first bus bar and a second bus bar which are oppositely arranged in a first direction, and a first electrode finger strip positioned on the first bus bar and a second electrode finger strip positioned on the second bus bar; the length extension directions of the first bus bar and the second bus bar are the same, the first bus bar and the second bus bar extend along a second direction, the first direction and the second direction are parallel to the plane of the substrate, and the first direction and the second direction are intersected;
forming a dielectric layer on one side of the interdigital electrode, which is away from the substrate;
forming a heat conduction layer on one side of the dielectric layer, which is away from the substrate;
the heat conduction layer is subjected to graphic processing to form a removal area, the removal area comprises a first groove area and a second groove area, the first groove area is located on one side of the first bus bar facing the second bus bar, the second groove area is located on one side of the second bus bar facing the first bus bar, the orthographic projection of the first groove area on the plane of the substrate at least covers the orthographic projection of the tail end area of the second electrode finger on the plane of the substrate, and extends along the second direction, and the orthographic projection of the second groove area on the plane of the substrate at least covers the orthographic projection of the tail end area of the first electrode finger on the plane of the substrate, and extends along the second direction.
17. A filter comprising the surface acoustic wave resonator of any one of claims 1-15.
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| CN202410036622.3A CN117713740A (en) | 2024-01-09 | 2024-01-09 | Surface acoustic wave resonator, preparation method thereof and filter |
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| CN202410036622.3A CN117713740A (en) | 2024-01-09 | 2024-01-09 | Surface acoustic wave resonator, preparation method thereof and filter |
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